Sensors

Many of the phenomena that we explore in our research can be used in sensors of various kinds. Liquid crystals are exceptionally responsive, smart materials, which can drastically change their structure in response to weak external stimuli (e.g. temperature changes, electrical or magnetic fields, mechanical stresses, …), leading to a distinct change in the macroscopic properties. These can be detected either directly by eye as a change in color or general appearance, or with an apparatus measuring the electrical or mechanical properties. Since the liquid crystal does not required a power supply to do the detection this renders them highly useful for truly autonomous sensors (for the cases that the response is to be detected by eye - otherwise a power supply will generally be required for the equipment sensing the response of the liquid crystal).

We are exploring this possibility in particular in the context of our work on electrospun polymer fibers functionalized with liquid crystals in the core. The extremely high surface-to-volume ratio of electrospun fibers renders an electrospun mat a very suitable configuration for a sensor, allowing a very fast and distinct response to a variety of stimuli. At present we have provided the proof of concept for fiber mats produced by liquid crystal coaxial electrospinning performing the function of temperature sensors and gas sensors (image on the left), respectively. It is a main current research thrust to develop this into truly useful sensing devices of novel types, in particular for integration in textiles.